From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NV0r2-0000MM-Ho for qemu-devel@nongnu.org; Wed, 13 Jan 2010 05:53:36 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NV0qx-0000LB-EH for qemu-devel@nongnu.org; Wed, 13 Jan 2010 05:53:35 -0500 Received: from [199.232.76.173] (port=34997 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NV0qx-0000L4-0b for qemu-devel@nongnu.org; Wed, 13 Jan 2010 05:53:31 -0500 Received: from mx1.redhat.com ([209.132.183.28]:65489) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NV0qw-0003dC-DO for qemu-devel@nongnu.org; Wed, 13 Jan 2010 05:53:30 -0500 Date: Wed, 13 Jan 2010 12:50:29 +0200 From: "Michael S. Tsirkin" Message-ID: <20100113105029.GB5077@redhat.com> References: <20100111171709.GD11936@redhat.com> <4B4CF97D.6070706@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B4CF97D.6070706@codemonkey.ws> Subject: [Qemu-devel] Re: [PATCH-RFC 03/13] virtio: add iofd/irqfd support List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: qemu-devel@nongnu.org On Tue, Jan 12, 2010 at 04:36:45PM -0600, Anthony Liguori wrote: > On 01/11/2010 11:17 AM, Michael S. Tsirkin wrote: >> Add binding API to set iofd/irqfd support. >> Will be used by vhost. >> >> Signed-off-by: Michael S. Tsirkin >> --- >> hw/virtio.c | 13 ++++++++++--- >> hw/virtio.h | 4 ++++ >> 2 files changed, 14 insertions(+), 3 deletions(-) >> >> diff --git a/hw/virtio.c b/hw/virtio.c >> index 8e3c9ad..b9ec863 100644 >> --- a/hw/virtio.c >> +++ b/hw/virtio.c >> @@ -572,6 +572,12 @@ VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size, >> return&vdev->vq[i]; >> } >> >> +void virtio_irq(VirtIODevice *vdev, VirtQueue *vq) >> +{ >> + vdev->isr |= 0x01; >> + virtio_notify_vector(vdev, vq->vector); >> +} >> + >> void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) >> { >> /* Make sure used ring is updated before we check NO_INTERRUPT. */ >> @@ -582,8 +588,7 @@ void virtio_notify(VirtIODevice *vdev, VirtQueue *vq) >> (vq->inuse || vring_avail_idx(vq) != vq->last_avail_idx))) >> return; >> >> - vdev->isr |= 0x01; >> - virtio_notify_vector(vdev, vq->vector); >> + virtio_irq(vdev, vq); >> } >> >> void virtio_notify_config(VirtIODevice *vdev) >> @@ -696,8 +701,10 @@ VirtIODevice *virtio_common_init(const char *name, uint16_t device_id, >> vdev->queue_sel = 0; >> vdev->config_vector = VIRTIO_NO_VECTOR; >> vdev->vq = qemu_mallocz(sizeof(VirtQueue) * VIRTIO_PCI_QUEUE_MAX); >> - for(i = 0; i< VIRTIO_PCI_QUEUE_MAX; i++) >> + for(i = 0; i< VIRTIO_PCI_QUEUE_MAX; i++) { >> vdev->vq[i].vector = VIRTIO_NO_VECTOR; >> + vdev->vq[i].vdev = vdev; >> + } >> >> vdev->name = name; >> vdev->config_len = config_size; >> diff --git a/hw/virtio.h b/hw/virtio.h >> index ca840e1..193b3f9 100644 >> --- a/hw/virtio.h >> +++ b/hw/virtio.h >> @@ -88,6 +88,8 @@ typedef struct { >> int (*load_config)(void * opaque, QEMUFile *f); >> int (*load_queue)(void * opaque, int n, QEMUFile *f); >> unsigned (*get_features)(void * opaque); >> + int (*set_irqfd)(void * opaque, int n, int fd, bool assigned); >> + int (*set_queuefd)(void * opaque, int n, int fd, bool assigned); >> > > I'd like to see us abstract things like irqfd a bit more. It should be > a first class object with an method to raise/lower. In fact, you can > probably just use qemu_irq. > > Regards, > > Anthony Liguori With a single provider, I fail to see the point of extra abstraction layers, and I have no idea how a good abstraction would look. Let's see when we have multiple implementations, then we can abstract them as appropriate. Also, irqfd does not have methods to raise/lower so qemu_irq is far from a good fit. -- MST